mkl_graph_mxv
mkl_graph_mxv
Computes a (masked) graph matrix-vector product.
Syntax
mkl_graph_status_t
mkl_graph_mxv (mkl_graph_vector_t
w
,
mkl_graph_vector_t
mask
,
mkl_graph_accumulator_t
accum
,
mkl_graph_semiring_t
semiring
,
mkl_graph_matrix_t
A
,
mkl_graph_vector_t
u
,
mkl_graph_descriptor_t
desc
,
mkl_graph_request_t
request
,
mkl_graph_method_t
method
);
Include Files
- mkl_graph.h
Description
The
mkl_graph_mxv
routine computes a (masked) graph matrix-vector product defined as w<mask> := accum(w, op(A)*u)
where
u
, w
are input and output vectors respectively, A
is the graph matrix, accum
is the optional binary operator to be used as an accumulator for the output vector, and mask
is an optional mask for the output vector. Possible modifications of the operation, including the matrix modifier
The expression op
, are defined through the operation descriptor desc
. The routine supports both single-stage and multistage execution modes (see Graph Operations) via the request parameter.op(
is evaluated over the algebraic semiring defined from the semiring parameter. The operation can be done in-place, meaning that the output vector can be aliased with the input vector or the mask. However, in this case the original data will be replaced. A
)*u
The
method
parameter is reserved for future use when an advanced user will be able to specify a particular method to be used for computations. Currently, only MKL_GRAPH_METHOD_AUTO
is supported.Even if the input vector is dense, the output vector can be sparse if the matrix has empty rows.
Multistage execution requires you to set the format of the output vector. Currently only the format matching the input vector is supported. In particular, you should allocate enough space for a dense vector and call
mkl_graph_vector_set_dense
in the multistage execution flow if the input vector is dense, even if the matrix has empty rows and sparse output is expected.Input Parameters
- mask
- A graph vector which contains the mask. If NULL, no mask is used.Currently, mask can only be used when the input vector is sparse.
- accum
- Binary operator to be used as an accumulator. Refer to Graph API Glossary for a list of possible options.The following accumulators are supported:MKL_GRAPH_ACCUMULATOR_NONE,MKL_GRAPH_ACCUMULATOR_PLUS(only forMKL_GRAPH_SEMIRING_PLUS_SECOND_FP32with a dense input vector and out of place output vector),MKL_GRAPH_ACCUMULATOR_MIN(only forMKL_GRAPH_SEMIRING_MIN_PLUS_INT32andMKL_GRAPH_SEMIRING_MIN_SECOND_INT32with a dense input vector and out of place output vector).
- semiring
- Algebraic semiring. Refer to Graph API Glossary for a list of possible options.The following semirings are supported:MKL_GRAPH_SEMIRING_PLUS_TIMES_INT32,MKL_GRAPH_SEMIRING_PLUS_TIMES_FP32,MKL_GRAPH_SEMIRING_PLUS_SECOND_FP32(for a dense input vector),MKL_GRAPH_SEMIRING_MIN_SECOND_INT32(for a dense input vector),MKL_GRAPH_SEMIRING_MIN_PLUS_INT32,MKL_GRAPH_SEMIRING_ANY_SECOND_INT32,MKL_GRAPH_SEMIRING_ANY_SECOND_FP32,MKL_GRAPH_SEMIRING_ANY_PAIR_BOOL(for a sparse input vector).
- A
- A graph matrix which contains the input matrixA.
- u
- A graph vector which contains the input vectoru.The types of indices and values of the matrixAand input vectorushould match (except for the values which can be unused if a corresponding flagMKL_GRAPH_MOD_ONLY_STRUCTUREis set in the descriptor for one of the input arguments).
- desc
- An operation descriptor. Refer to Graph API Glossary for a list of possible options. If NULL, no extra modifiers are used for the operation.Currently it is allowed to set:MKL_GRAPH_MOD_ONLY_STRUCTUREfor input matrix or input vector,MKL_GRAPH_MOD_TRANSPOSEfor the input matrix,MKL_GRAPH_MOD_COMPLEMENTfor the mask.
- request
- An operation request as defined in the multi-stage execution model.For single-stage execution, useRefer to Graph API Glossary for a list of possible options.MKL_GRAPH_REQUEST_COMPUTE_ALL. For multistage execution, stagesMKL_GRAPH_REQUEST_FILL_NNZandMKL_GRAPH_REQUEST_FILL_ENTRIESshould be used.
- method
- A method which should be used for computing the result. For automatic choice, useMKL_GRAPH_METHOD_AUTO. Refer to Graph API Glossary for a list of possible options.Currently onlyMKL_GRAPH_METHOD_AUTOis supported by this routine.
Output Parameters
- w
- A graph vector which contains the output vectorw. If vectorwis non-empty on entry to the routine, its data is overwritten by the result of the computations. Also, in this case the type of values ofwmust match the type of the semiring values.
Return Values
The function returns a value indicating whether the operation was successful or not and why. Refer to Graph API Glossary for a list of possible options.
Optimization Notice
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Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.
Notice revision #20110804
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This notice covers the following instruction sets: SSE2, SSE4.2, AVX2, AVX-512.